- A novel synthesis of imidazo[2,1-d][1,2,4]triazine and imidazo[2,1- dl]1,2,5]triazepine derivatives via ketene-N,N-acetal
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The ketene-S,S-acetal I was prepared under phase-transfer catalysis (PTC) in benzene-carbonate two phase system using tetrabutylammonium bromide as the catalyst. Upon treatment with 1,2-diaminoethane, followed by hydrolysis with sodium methoxide, I gave 2-(2-oxopropylidene) imidazoline III. Bromination of III and replacement of bromine by hydrazine afforded 2- (1-hydazino-1,2-oxopropylidene) imidazoline V. Compound V was used as a precursor for the preparation of the previously unreported fused nitrogen heterocyclic ring system of imidazotriazine VI, VIII, XI, XII and imidazotriazepine IX, X.
- El-Saghier, Ahmed M. M.,Maihub, Abdussalam A.,Al-Shirayda, Hatif A.
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- A new protocol for the synthesis of N(1)-unsubstituted 2-substituted 2 imidazolines
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Lateral metallation at C-2(α) of 1-tert-butoxycarbonyl-2-methyl-2- imidazoline followed by reaction with a range of C-electrophiles and deprotection with TFA reliably affords N(1)-unsubstituted 2-substituted 2- imidazolines; P- or Se-electrophiles lead to 2-alkenyl-2-imidazolines via Wadsworth-Emmons or selenoxide elimination protocols. (C) 2000 Elsevier Science Ltd.
- Jones, Raymond C. F.,Dimopoulos, Paschalis
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p. 2061 - 2074
(2007/10/03)
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- Synthesis of Acetyl-Substituted Heterocyclic Ketene Aminals and Their Deactylation Reaction
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The acetyl-substituted heterocyclic ketene aminals 3-6 were synthesized by the reaction of ketene dithioacetals 2 with diamines.The deacetylation of heterocyclic diacetyl ketene-aminals by alkali was studied, and the corresponding monoacetyl derivatives were studied.
- Wang, He-Ting,Wang, Xiao-Jun,Huang, Zhi-Tang
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p. 2141 - 2145
(2007/10/02)
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